The National Breast Cancer Tissue Resource has been a core component of this SPORE program since its inception in 1992. This Resource has a long track record of prioritizing requests and distributing tissue to qualified breast cancer reseaachers both within the SPORE network and outside -- it has distributed more than 10,000 human breast tissues to 78 investigators throughout the world. Despite disastrous flooding last June that destroyed more than 65,000 specimens, this Tissue Resource currently maintains more than 11,000 permanent sections that were created from frozen tissues, and continues to provide tissues to researchers. The Tissue Resource will now be rebuilt and expanded using retrospectively identified paraffin blocks from patients who were previously diagnosed with breast diseases, along with prospectively collected paraffin blocks and frozen tissue from patients with newly diagnosed breast cancer. It is anticipated that approximately 20,000 retrospectively identified paraffin blocks will be added to the inventory during this funding period. Paraffin blocks from an additional 2,000 newly diagnosed patients and frozen tissues from at least 625 of these patients will be prospectively obtained with appropriate informed consent. The Tissue Resource will also receive, process, store, and deliver tissues that are collected as part of clinical trials conducted as SPORE projects, for which patients will be enrolled at Baylor College of Medicine and at collaborating institutions in several other cities, as indicated in each project. All components are in place to maintain this tissue resource, store the tissue, and link the tissue with appropriate pathological, clinical, and family history data. There is excellent informatics and database support for this Resource in the Biostatistics and Data Management Core, with additional expertise in the remainder of the Breast Center.